Control of fuel-injection engines



June 2l, 1949. A F, SANDERS CONTROL OF FUEL INJECTION ENGINES FiledApril 16, 1947 FIC l FIG Z- FIG 3 JNVENToR. Jah/T3719 Patented June 2l,1949 UNITED STATES PATENT OFFICE Application April 16, 1947, Serial No.741,807 In Great Britain September 9, 1942 Section 1, Public Law 690,August 8, 1946 Patent expires September 9, 1962 3 Claims.

This invention relates to a fuel-injection engine such as has a device,responsive to the lubrication pressure of the engine, which isassociated directly or indirectly with the main fuel control member ofthe fuel pumping unit so as to cut olf the fuel delivery if thelubrication pressure falls below a predetermined value.

According to the invention, the device also limits the maximum fueldelivery in running conditions. Furthermore, the device is preferablyadapted also to provide an excess fuel delivery (beyond the normalmaximum) at starting.

In the accompanying drawings:

Figure 1 is a sectional elevation of a device according to theinvention;

Figure 2 is a plan thereof; and

Figure 3 is a fragmentary elevational view showing an alternative meansof operation.

In the construction shown the device is carried by a bracket I bolted orotherwise secured against an appropriate wall of the fuel pumping unit II, the device comprising a vertical cylinder l2 connected at its lowerend to a pipe I 3 leading to the lubrication system of the engine (notshown) so as to receive the pressure thereof. In the cylinder isdisposed a plunger I4 biassed downwardly by a combined torsion andtension spring I5, a stop being provided to limit the outward movementof the plunger. The latter has a cylindrical portion I6 outside thecylinder, and above that a truncated cone portion I 'I, which parts cancoact, dependently upon the lubrication pressure, with a roll-er I8carried at the end of the main fuel control member I9 of the pump unit.On one side of the truncated cone portion is milled a slot 20 of a widthto receive the roller, the bottom of the slot curving out to join thecylindrical portion I6 of the plunger.

Normally the slot is away from the roller, as shown by Figure 1, andwhen the engine is stationary the roller engages the upper end (maximumdiameter) of the truncated cone portion, the fuel delivery then beingcut ofl", as shown by the full lines. To start the engine the plunger isturned through 180 to bring the slot 20 of the truncated cone portioninto alignment with the roller, thus subjecting the biassing spring I toa torsional stress, and the main fuel control member I9 can then beforced by the normal governor spring into a position in which excessfuel, f

(Cl. 12B-140) 2 the roller to the left (Figure 1) and out of the slot20. Also, the lubrication pressure building up beneath the plunger willforce this outwardl;T against the tension of the biassing spring I5until the roller is quite clear of the slot 20, and, in fact, thecylindrical portion I6 of the plunger is in line with the roller, asshown by the chain lines of Figure 1. The cylindrical portion I6 willthen determine the maximum fuel delivery as long as the lubricationpressure is maintained. When the roller is quite clear of the slotl 2%the torsion of the spring I 5 will twist the plunger to move the slotout of alignment with the roller, i. e., back to the position of Figure2.

In the event, however, of the lubrication pressure failing, the springacting upon the plunger will return the parts to the engine-stationaryposition shown by the full lines of Figure 1, the inclined surface ofthe truncated cone portion acting on the roller to force the main fuelcontrol member I9 to the fuel cut-off position. The roller may besupported against side thrust as necessary.

To stop the engine the plunger can be pushed down manually and held downuntil the engine is stopped; and, if desired, provision may be made foreffecting this, or for turning the plunger to the starting position,from the dashboard or the like accessible place in the case of amotor-vehicle having an engine fitted with the device of the invention.

A remote control means is illustrated in Figure 3, in which the plungeris shown in the stop position. The end 22 of a Bowden or like control iswound round and appropriately secured to an exposed portion of theplunger. In addition, a Bowden or like control 23 is connected to alever 24 the free end of which is adapted to coact with the head ofl thetruncated cone portion Il of the plunger. The drawing shows the partswhen the control 23 has been pulled to cause the lever 24 to force theplunger downwardly against the oil pressure, thereby stopping theengine. By means of the control 22 the plunger can be rotated through tobring the slot 20 into co-operation with the roller I 8, whereby toplace the main fuel control member in the starting position, as abovedescribed. As the engine starts the roller I8 will tend to be withdrawnfrom the slot 2t and the oil pressure will tend to lift the slot 2liclear of the roller, such that the plunger can be turned by the springl5 back to the normal running position-assuming, of course, that thecontrol 22 has not been held in the starting position and that the lever24 is likewise free to turn from the position shown in Figure 3.

Furthermore, by arranging the cylindrical portion I6 to be eccentric, orshaped as a cam, as indicated by the dash-dot line 16a: in Figure 2, andby providing means for manually twisting the plunger when desired, themaximum fuel delivery can be adjusted when desired.

Furthermore, electric contacts may be arranged and connected up toilluminate a pilot light in the event of the lubrication pressurefailing, so as to obviate the likelihood of the driver attempting torestart the engine without investigating the trouble.

Obviously, instead of using a piston form of plunger, use may be made ofa diaphragm or bellows device, or some other form of hydraulic devicemay be used, provision being made for its torsional control as well asfor its axial movement.

What I claim as my `invention and desire to secure by Letters Patent ofthe United States is:

1. For a fuel-injection engine, the combination with a fuel pumping unithaving a main fuel control member, of a plunger having a head coactingwith said member, said head having a frusta-conical portion the smallerdiameter of which is adjacent an eccentric cylindrical portion, meansbiassing said plunger to a position in which the larger diameter of saidfrustoconical portion engages said member to cut off the fuel delivery,means for applying the lubrication pressure of the engine to saidplunger to force it against the biassing means so that, when the engineis running normally, said cylindrical portion engages said member tolimit the maximum fuel delivery, and means for partially rotating theplunger to control the maximum fuel delivery when the engine is runningnormally.

2. For a fuel-injection engine, the combination with a fuel pumping unithaving a main fuel control member, ofv a plunger having. a head coactingwith said member, said head having a frusto-conical portion the smallerdiameter of which is adjacent a cylindrical portion, means biassing saidplunger to a position in which the larger diameter of saidfrusto-conical portion engages said member to cut off the fuel delivery,means for applying the lubrication pressure of the engine to saidplunger to force it against the biassing means so that, when the engineis run- 5G ning normally, said cylindrical portion engages said memberto limit the maximum fuel delivery, said plunger having a longitudinalperipheral groove through the frusto-conical portion to receive theadjacent end of said member, the bottom wall of said groove being nearerthe axis of the plunger than the periphery of said cylindrical portion,and means for partially rotating the plunger to enable said member toenter said groove and to thus increase the maximum fuel delivery abovenormal when the engine is being started.

3. For a fuel-injection engine, the combination with a fuel pumping unithaving a main fuel control member, of an angularly and axially movableplunger having a head coacting with said member, said head having afrusto-conical portion the smaller diameter of which is adjacent a camportion, and said frusto-conical portion having a longitudinalperipheral groove in it to receive the adjacent end of said member, thebottom Wall of said groove being nearer the axis of the plunger than theperiphery of said cam portion, means biassing said plunger to a positionin which the larger diameter of said frustoconical portion engages saidmember to cut off the fuel delivery, with said groove spaced angularlyfrom said member, means for applying the lubrication pressure of theengine to said plunger to force it axially against the biassing means sothat, when the engine is running normally, said cam portion engages saidmember to limit the maximum fuel delivery, and means for partiallyrotating the plunger 'against said biassing means to control the maximumfuel delivery when the engine is running normally and to enable saidmember to enter saidgroove to increase the maximum fuel delivery abovenormal when the engine is being started.v 1

ARTHUR FREEMAN SANDERS.

REFERENCES CITED They following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,201,123 Davis May 14, 194i)FOREIGN PATENTS Number Country Date 408,760 Great Britain .Apr. 19, 1934

